Watch: How Sailor Brinkley Cook Helps Mom Christie Brinkley Navigate Social MediaSailor Brinkley Cook is modeling social media behavior for her mom. While Christie Brinkley has offered modeling advice to her 27-year-old daughter-whom she shares with ex-husband Peter Cook-she's also gotten plenty of tips in return on how to navigate her social accounts. "I'm teaching her TikTok basically," Sailor exclusively shared with E! News at the New York Gala screening of Brunello: The Gracious Visionary April 14. "Social media, TikTok, posting, being more on Instagram.